This invention pertains to pen carriages for ink-jet printers.
Presently available are ink-jet printer pens that contain only black ink (hereafter referred to as black pens). Also available are pens that carry inks of subtractive primary colors (cyan, magenta, and yellow), which may be used for printing a variety of colors, including black (these pens hereafter referred to as color pens).
Certain ink-jet printers use pens that include a plurality of nozzles through which ink drops are discharged. Each pen nozzle has associated with it a thin-film resistor that is selectively driven (heated) with sufficient current for vaporizing ink in the vicinity of the nozzle, thereby forcing through the nozzle a drop of ink. Drive lines to each nozzle resistor are carried upon a circuit that is mounted to the exterior of the pen. Circuit contact pads on the pen-mounted circuit connect with mating pads on a corresponding circuit that is mounted to the carriage.
An ink-jet printer manufactured by Hewlett-Packard Company and designated the "DeskJet" printer includes a carriage for holding a black pen. The carriage is reciprocated across the width of a sheet of paper that is advanced through the printer.
The carriage includes features that mate with reference members formed on the pen. The pen is installed in the printer by lowering the pen into a chute formed in the carriage. The reference members of the pen are guided by the chute into contact with the carriage features. The pen is then manipulated to pivot about the contacting reference members and features so that the top of the pen moves into engagement with a spring clip mounted to the carriage. When the pen top is so engaged, the pen is clamped to the carriage with the contact pads of the pen-mounted circuit pressed against the contacts pads on the carriage-mounted circuit.
It has been found to be advantageous to configure an ink-jet printer for interchangeably using a black pen and a color pen. The color pen, like the black pen, includes a pen-mounted circuit having exposed contact pads that are configured to connect with the pads on the carriage-mounted circuit. The overall shape of the color pen, however, is somewhat different from that of the black pen.